package cn.univyz.bfyweb.helper;

import cn.univyz.bfyweb.util.CollectionUtil;
import cn.univyz.bfyweb.util.PropsUtil;
import org.apache.commons.dbcp2.BasicDataSource;
import org.apache.commons.dbutils.QueryRunner;
import org.apache.commons.dbutils.handlers.BeanHandler;
import org.apache.commons.dbutils.handlers.BeanListHandler;
import org.apache.commons.dbutils.handlers.MapListHandler;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import java.io.BufferedReader;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.util.ArrayList;
import java.util.List;
import java.sql.Connection;
import java.sql.SQLException;
import java.util.Map;
import java.util.Properties;

/**
 * 数据库操作助手类
 */
public final class DatabaseHelper {
    private static final Logger LOGGER = LoggerFactory.getLogger(DatabaseHelper.class);
    private static final QueryRunner QUERY_RUNNER;
    private static final ThreadLocal<Connection> CONNECTION_HOLDER;
    private static final BasicDataSource DATA_SOURCE;
    static {
        CONNECTION_HOLDER = new ThreadLocal<Connection>();

        QUERY_RUNNER = new QueryRunner();

        Properties conf = PropsUtil.loadProps("config.properties");
        String driver=conf.getProperty("jdbc.driver");
        String url=conf.getProperty("jdbc.url");
        String username=conf.getProperty("jdbc.username");
        String password=conf.getProperty("jdbc.password");

        DATA_SOURCE=new BasicDataSource();
        DATA_SOURCE.setDriverClassName(driver);
        DATA_SOURCE.setUrl(url);
        DATA_SOURCE.setUsername(username);
        DATA_SOURCE.setPassword(password);

    }

    /**
     * 获取数据库连接
     */
    public  static Connection getConnection() {
        Connection conn = CONNECTION_HOLDER.get();
        try{
            conn= DATA_SOURCE.getConnection();
        }catch (SQLException e){
            LOGGER.error("get connection failure",e);
            throw new RuntimeException(e);
        }finally {
            CONNECTION_HOLDER.set(conn);
        }
        return conn;
    }

    /**
     * 关闭数据库连接
     */
    /*
    public  static void closeConnection(){
        Connection conn =CONNECTION_HOLDER.get();
        if (conn != null){
            try{
                conn.close();
            }catch (SQLException e){
                LOGGER.error("close connection failure",e);
                throw new RuntimeException(e);
            }finally {
                CONNECTION_HOLDER.remove();
            }
        }
    }
    */


    /**
     * 查询实体列表
     */
    public static <T>List<T>  queryEntityList(Class<T> entityClass, String sql, Object... params){
        List<T> entityList;

        try{
            Connection conn=getConnection();
            entityList = QUERY_RUNNER.query(conn,sql,new BeanListHandler<T>(entityClass),params);
        }catch (SQLException e){
            LOGGER.error("query entity list failure",e);
            throw new RuntimeException(e);
        }
        return entityList;
    }

    /**
     * 查询实体
     */
    public static <T>T queryEntity(Class<T> entityClass,String sql,Object... params){
        T entity;

        try{
            Connection conn=getConnection();
            entity = QUERY_RUNNER.query(conn,sql,new BeanHandler<T>(entityClass),params);
        }catch (SQLException e){
            LOGGER.error("query entity failure",e);
            throw new RuntimeException(e);
        }
        return entity;
    }

    /**
     * 执行查询语句
     */
    public static List<Map<String,Object>> executeQuery(String sql,Object... params){
        List<Map<String,Object>> result;
        try{
            Connection conn = getConnection();
            result=QUERY_RUNNER.query(conn,sql,new MapListHandler(),params);
        }catch (Exception e){
            LOGGER.error("execute query failure",e);
            throw new RuntimeException();
        }
        return  result;
    }

    /**
     * 执行更新语句（包括update,insert,delete）
     */
    public static int executeUpdate(String sql,Object... params){
        int rows=0;
        try{
            Connection conn = getConnection();
            rows=QUERY_RUNNER.update(conn,sql,params);
        }catch (SQLException e){
            LOGGER.error("execute update failure",e);
            throw new RuntimeException(e);
        }
        return rows;
    }

    /**
     * 插入实体
     */
    public static <T> boolean insertEntity(Class<T> entityClass,Map<String,Object> fieldMap) {


        if (CollectionUtil.isEmpty(fieldMap)){
            LOGGER.error("can not insert entity: fieldMap is empty");
            return false;
        }

        String sql="INSERT INTO " + getTableName(entityClass);
        StringBuilder columns =new StringBuilder("(");
        StringBuilder values=new StringBuilder("(");
        for (String fieldName : fieldMap.keySet()){
            columns.append(fieldName).append(", ");
            values.append("?, ");
        }
        columns.replace(columns.lastIndexOf(", "), columns.length(),")");
        values.replace(values.lastIndexOf(", "), values.length(), ")");
        sql += columns + " VALUES " + values;
        Object[] params =fieldMap.values().toArray();
        return executeUpdate(sql,params) == 1;

    }

    /**
     * 更新实体
     */
    public static <T> boolean updateEntity(Class<T> entityClass, long id,Map<String,Object> fieldMap){
        if (CollectionUtil.isEmpty(fieldMap)){
            LOGGER.error("can not update entity: fieldMap is empty");
            return false;
        }

        String sql ="UPDATE " + getTableName(entityClass) + " SET ";
        StringBuilder columns = new StringBuilder();
        for (String fieldName : fieldMap.keySet()) {
            columns.append(fieldName).append("=?, ");
        }
        sql += columns.substring(0,columns.lastIndexOf(", ")) + " WHERE id=?";
        List<Object> paramList = new ArrayList<Object>();
        paramList.addAll(fieldMap.values());
        paramList.add(id);
        Object[] params = paramList.toArray();


        return executeUpdate(sql,params) == 1;
    }

    /**
     * 删除实体
     */
    public static <T> boolean deleteEntity(Class<T> entityClass, long id){
        String sql="DELETE FROM " + getTableName(entityClass) + " WHERE id=?";

        return executeUpdate(sql,id) ==1;
    }

    /**
     * 执行SQL文件
     * @param filePath
     */
    public static void executeSqlFile(String filePath){

        InputStream is=Thread.currentThread().getContextClassLoader().getResourceAsStream(filePath);
        BufferedReader reader = new BufferedReader(new InputStreamReader(is));
        String sql;

        try {
            while((sql=reader.readLine()) !=null){
                executeUpdate(sql);
            }
        }catch (Exception e){
            LOGGER.error("execute sql file failure", e);
            throw new RuntimeException(e);
        }

    }

    public static String getTableName(Class<?> entityClass){
        return entityClass.getSimpleName().toLowerCase();
    }


}
